ISL6566CRZ Intersil, ISL6566CRZ Datasheet - Page 12

• Manufacturer Part Number: ISL6566CRZ
• Description: IC CTRLR PWM BUCK 3PHASE 40QFN
• Manufacturer: Intersil

Specifications of ISL6566CRZ

• Applications: Controller, Intel VRM9, VRM10, and AMD Hammer Applications
• Voltage - Input: 3 ~ 12 V
• Number Of Outputs: 1
• Voltage - Output: 0.84 ~ 1.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 40-VFQFN, 40-VFQFPN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The ISL6566 supports MOSFET r
sample each channel’s current for channel-current balance.
The internal circuitry, shown in Figure 5 represents channel
n of an N-channel converter. This circuitry is repeated for
each channel in the converter, but may not be active
depending on the status of the PVCC3 and PVCC2 pins, as
described in the PWM Operation section.
The ISL6566 senses the channel load current by sampling
the voltage across the lower MOSFET r
Figure 5. A ground-referenced operational amplifier, internal
to the ISL6566, is connected to the PHASE node through a
resistor, R
the voltage drop across the r
while it is conducting. The resulting current into the ISEN pin
is proportional to the channel current, I
sampled and held as described in the Current Sampling
section. From Figure 5, the following equation for I
derived where I
I
n
SAMPLE
ISL6565A INTERNAL CIRCUIT
HOLD
FIGURE 5. ISL6566 INTERNAL AND EXTERNAL CURRENT-
=
I
&
I
n
L
r
----------------------
DS ON
R
I
SEN
ISEN
ISEN
(
FIGURE 4. SAMPLE AND HOLD TIMING
SENSING CIRCUITRY FOR CURRENT BALANCE
OLD SAMPLE
CURRENT
=
)
. The voltage across R
L
I
L
is the channel current.
r
------------------------- -
+
DS ON
R
-
ISEN
PWM
(
)
SWITCHING PERIOD
SAMPLING PERIOD
DS(ON)
12
I
L
ISEN(n)
EXTERNAL CIRCUIT
TIME
CHANNEL N
LOWER MOSFET
DS(ON)
I
SEN
R
of the lower MOSFET
ISEN
ISEN
L
. The ISEN current is
DS(ON)
current sensing to
V
is equivalent to
IN
+
NEW SAMPLE
CURRENT
CHANNEL N
UPPER MOSFET
-
I
, as shown in
L
r
DS ON
n
I
L
is
(
(EQ. 3)
)
ISL6566
ISL6566
Output Voltage Setting
The ISL6566 uses a digital to analog converter (DAC) to
generate a reference voltage based on the logic signals at the
VID pins. The DAC decodes the 5 or 6-bit logic signals into
one of the discrete voltages shown in Tables 2, 3, and 4.
Each VID pin is pulled up to an internal 1.2V voltage by a
weak current source (40µA current), which decreases to 0 as
the voltage at the VID pin varies from 0 to the internal 1.2V
pull-up voltage. External pull-up resistors or active-high
output stages can augment the pull-up current sources, up to
a voltage of 5V.
.
The ISL6566 accommodates three different DAC ranges:
Intel VRM9.0, AMD Hammer, or Intel VRM10.0. The state of
the VRM10 and VID12.5 pins decide which DAC version is
active. Refer to Table 1 for a description of how to select the
desired DAC version.
TABLE 2. AMD HAMMER VOLTAGE IDENTIFICATION CODES
VID4
DAC VERSION
AMD HAMMER
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
VRM10.0
VRM9.0
TABLE 1. ISL6566 DAC SELECT TABLE
VID3
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
VID2
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
VRM10 PIN
high
low
low
VID1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
VID0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
VID12.5 PIN
high
low
-
March 9, 2006
VDAC
0.800
0.825
0.850
0.875
0.900
0.925
0.950
0.975
1.000
1.025
1.050
1.075
1.100
1.125
1.150
1.175
1.200
1.225
1.250
1.275
1.300
FN9178.4
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